"Based on the preliminary earthquake parameters... hazardous tsunami waves are possible for coasts located within 300 Kilometres of the earthquake epicenter," the Hawaii-based monitor warned after the shallow quake in waters around the island nation of Vanuatu. The quake's epicenter was around 200 kilometres (124 miles) north-west of Vanuatu's Port-Olry, according to geological monitor USGS which later revised the magnitude of the tremor down to 6.9. It also reported a second quake of magnitude 6.3 nearby. Earthquakes are common in Vanuatu, a low-lying archipelago that straddles the tectonic Ring of Fire, an arc of seismic activity stretching through Southeast Asia and across the Pacific basin. (Bssnews)